Fix typo in documentation.
SI-7852 Test to show the status quo bytecode for "" == ...

Will be somewhat leaner after the next commit.
SI-7852 Omit null check for "".==

Although the same the code would be later optimized by -Yconst-opt,
we can offer the same lean byte code to those compiling without that
option by being more discerning when translating ==.

This helps people using bytecode based code coverage tools
such as jacoco that would emit "branch not covered" warnings
for the impossible null check.
SI-7852 Test to show status quo of for SomeModule.==

For which we can also elide the null check, and will in the
next commit.
SI-7848 Xlint says what looks interpolated

The motivating use case was an Expecty debug string
getting flagged for `$eq`.

The test case demonstrates a different bug, in which
the position of the literal tree is changed when typer
gets rid of the unused local, so that when the tree is
re-typed in erasure, a second, spurious warning is
emitted at the start of the method. Specifically, the
second warning is not suppressed because of the
different position.
SI-7852 Omit null check for SomeModule.==

For the same reasons outlined in the previous commits.
SI-7852 Refactor null-elision tests to be more focussed

 - Directly count null checks, rather than diffing the textual
   bytecode of the entire method
 - Add a test to show that the LHS needs to be a direct module
   reference, not just a tree with a module type, to elide the
   null check.
add syntactic extractor for assignment-like trees

There are three kinds of assign-like trees:

1. Assign(lhs, rhs)                          // $lhs = $rhs
3. AssignOrNamedArg(lhs, rhs)                // $lhs = $rhs
2. Apply(Select(f, nme.update), args :+ rhs) // $f(..$args) = $rhs

New syntactic combinator unifies all of them and lets users not to think
about these implementations details.
SI-7855 No missing interpolator warning post-typer

Avoid extra work, extra warnings.
SI-7848 Xlint no warn on $sym with params

This idea brought to you by retronym.
Upgrade: starr=M5, partest=RC5, xml=RC4, parsers=RC2.
Follow good interrupt discipline in Response

Restores the interrupted status of the waiting thread after catching
an InterruptException.
SI-7725 - Vector concatenation is unreasonably slow

Rewrote ++ to use append or prepend when adding small collections to the end
or beginning of vectors.  This solves the extra-O(n) problem for addition of
single elements reported in SI_7725.

Renamed LgConcatFaster to Log2ConcatFaster (more widely recognizable).
SI-7864 Harden "looks like an interpolated String" warning

We can't rely on the qualifier of an `Apply` having a non-null
symbol in general.
Merge pull request #2954 from retronym/ticket/7852

Avoid null checks when emitting "".== and SomeModule.==
Merge pull request #2974 from retronym/ticket/7864

SI-7864 Harden "looks like an interpolated String" warning
Merge pull request #2968 from huitseeker/interrupt-kosherness

Follow good interrupt discipline in Response
Merge pull request #2962 from densh/topic/syntactic-assign

Quasiquotes: add syntactic extractor for assignment-like trees
Merge pull request #2953 from jiaweihli/master

Fix typo in documentation.
Merge pull request #2956 from som-snytt/issue/7848-forgotten-interp-msg

SI-7848 Xlint says what looks interpolated